ISO International Standard

The principle of the method specified is exposing and processing samples as specified, obtaining density measurements from the resultant images to produce a sensitometric curve from which values are taken and used to determine ISO speed and ISO range. The method applies to vesicular microfilms which have their principal spectral sensitivity in the region of 350 nm to 450 nm and are used to produce negative-appearing images from positive originals and positive-appearing images from negative originals.